[gnome-shell] ci: Handle merge requests for non-master branches

[Florian Müllner <fmuellner src gnome org>]

commit 8db4f3c67f33fcad31c0b9cafa141392b121cd14
Author: Florian Müllner <fmuellner gnome org>
Date:   Tue Apr 23 19:04:21 2019 +0200

    ci: Handle merge requests for non-master branches
    
    If we don't find a branch that matches the branch used in the merge
    request, we currently fall back to the non-merge-request matching,
    i.e. first try the current shell branch, then fall back to master.
    
    This should work for commits to upstream branches, but not for merge
    requests to a stable branch. For those, the target branch name is
    a better fallback.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/509

 .gitlab-ci/checkout-mutter.sh | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/.gitlab-ci/checkout-mutter.sh b/.gitlab-ci/checkout-mutter.sh
index 7eb5c2974..618ad2582 100755
--- a/.gitlab-ci/checkout-mutter.sh
+++ b/.gitlab-ci/checkout-mutter.sh
@@ -19,6 +19,8 @@ if [ "$CI_MERGE_REQUEST_TARGET_BRANCH_NAME" ]; then
   echo Looking for $merge_request_branch on remote ...
   if git fetch -q $merge_request_remote $merge_request_branch; then
     mutter_target=FETCH_HEAD
+  else
+    mutter_target=origin/$CI_MERGE_REQUEST_TARGET_BRANCH_NAME
   fi
 fi